North and South Korea share a peninsula that lies between the Yellow Sea and the Sea of Japan. Much of the peninsula is hilly or mountainous with hills rising above 3,000 feet in the South and over 6,000 feet in the North.

Korea has a distinct continental climate even though it is surrounded by water on three sides. Despite its more northerly location, like most of eastern Asia, Korea's climate is strongly influenced by the annual reversal of monsoon winds. During the winter monsoon, which dominates from early November to late April, very cold north and northwesterly winds blow off the continent around the strong Siberian High. As a result, winters are cold and rather snowy. In May, the summer monsoon sets in and south-southeasterly winds develop bringing relatively warm and moist Pacific air. Summers are warm and rather wet.

Temperatures during the cold winter are often below freezing and can drop to 0°F or lower. Strong winds can bring dangerously low wind chills. In summer, some days are very muggy and uncomfortable with temperatures occasionally reaching into the 90s (°F) or even topping 100°F in the lower elevations, even in the North.

Precipitation occurs in all seasons, but there is a distinct summer maximum. In winter, the precipitation comes from disturbances or frontal systems from the west, and mostly falls in the form of snow. In the warmer months, disturbances from the west can bring rain or showers, some of which can be heavy as these systems tap the warm, moist Pacific air. About once a year on average, usually between June and September, a typhoon moving north from the South China Sea can bring especially heavy rains and strong winds.